Bio-molecules (Macromolecules)

Large molecules made up of atoms that sustain life

• Carbohydrates - fuels brain.
• Proteins - enables functions.
• Lipids (fats) - form membranes.
• Nucleic Acids - part of DNA.

All cell types can produce all four macromolecules (and you can get them from food).

Carbs vs Lipids

• Simple Carbs (Simple Sugars) - Quick energy release.
  • These are easily broken down.
  • One monomer - monosaccharides (sa. glucose).
  • Two monomers - disaccharides (sa. sucrose).
• Complex Carbs (Complex Sugars) - Time-release energy.
  • These take some amount of time to break down.
  • Polysaccharide (many monomer) chains (sa. starch).

Structure = Function

Think screwdriver vs. hammer.

• Building block of bio-molecules is a monomer.
• Polymerization - monomers (repeating units) are bonded in varying lengths (polymers).

Types of Body Fat

These are made of lipids.

Brown Fat

Generates body heat.

White Fat

Energy storage.

Beige Fat

White fat that acts like brown fat.

Other Lipids

• Steroids
• Phosphilipids
• Waxes

Steroids (Hormones)

Rigid ring structure, no tail, allows it to last longer in the bloodstream.

Phosphlipids

Two tails - better for cell membranes. Allows them to connect together and be semi-permeable.

Carbohydrates

Not all carbs are digestible due to their rigid chains (sa. fiber). Made of carbon-hydrogen-oxygen.

Properties of Lipids

Mainly used for energy. They generally have more bonds than carbohydrates, so they function better for long-term energy storage. They take up less space b/c they don't attract water.

Non-polar, fats, insoluble in water. Have more energy due to many c-H bonds (carbon-hydrogen tail).

• Hydrophilic head - glycerol.
• Hydrophobic tail - fatty acids.

Energy Release

Energy release is how many bonds could be broken between monomers; not the number of monomers themselves.

Bond breaking - endothermic. Bond making - exothermic. (Like compressed springs).

Dietary Fats

Saturated Fats

Straight chains pack together tightly. These are harder to break down and move along the bloodstream, so they can clog arteries and such.

Unsaturated Fats

Kinked chains cannot be tightly packed. These are liquid at room temperature.

Triglycerides

Main lipid in our diet. Three fatty-acid tails. The head/tail combo (glycerol head + fatty acid tail) is one monomer.

Energy Expenditure

Prolonged exercise - after 30min, your body shifts from carbs to fats.

Waxes

Strongly hydrophobic, one long fatty acid chain, no water-loving head.